Automatic strip grinder



Feb. 27, 1940.

H. M. BROWN 2,191,814

AUTOMATIC STRIP GRINDER Filed Aug. 26, 1938 3 SheetsSheet 1 a x v F X\\\\\ Ki J,

' lNVENTO R HERMAN M. BROWN BY I'ATTORNEY Q Feb. 27, 1940. BROWN 2,191,814

AUTOMATIC STRIP GRIIINDBR Filbd Aug. 26, 1938 3 Sheets-Sheet 2 .JNVENTOR HERMAN BROWN Q ATTORNEY I H. M. snowu AUTOMATIC STRIP GRINDER Feb. 27, 1940. 2,191,814

3 Shgets-Sheet 3 'Filcd Aug. 26, 1938 INVENTOR HERMAN NLBROWN ATTORNEY Patented Feb. 27, 1940 UNITED STATES 2,it1,8l4

PATENT orrice signor to The International Nickel Company, Inc., New York, N. Y., a corporation of Delaware Application August 26,

14 Claims.

The present invention relates to strip grinders, and, more particularly, to a strip grinder capable of grinding both sides of a strip or sheet of metal to plane surfaces.

ood surface finish, or high surface polish, it is necessary in many instances to grind the surfaces of the sheet or strip to remove surface defects before the last rolling operation. Here- 'tofore the grinding operation has generally been performed on a grinding table, on. which successive lengths of the strip were ground by a rotating grinding wheel suspended by means of a long connecting 'rod from an overhead pivot and swung back and forth by the operator along the strip. During grinding the strip lay stationary on a. supporting table, being moved only after a length had been finished. Due to the pendulum-like motion of the grinding wheel, the

strip had a series of transverse cylindrical concavities on the ground surface each of which abutted, at its lateral boundaries, against adjacent concavities. These concavities were undesirable because of the difficulties experienced in cold rolling the ground strip, particularly in delivering the strip from the cold rolling mill. In carrying out the grinding by this method, moreover, the strip was almost invariably ground thinner at one or both edges than in the middle.

As a result, when the ground strip was further rolled the thicker sections were extruded or elongated to a greater extent than the thinner sections, producing a warped and twisted strip.

It is an object of the present invention to pro- 3 .vide a strip grinding machine capable of grinding one or both sides of a strip of metal or alloy to substantially uniform and contant gauge throughout its length and width.

It is another object of the invention to pro vide a strip grinding machine capable of grinding a plurality of strips simultaneously, regardless of their widths and thicknesses.

A further object of the invention contemplates the provision of a strip grinding machine which is practically automatic in operation, which is simple yet sturdy, and reliable in operation, and

which can be manufactured and operated at relatively'glow cost.

Other objects and advantages of the present invention will become apparent from the following description, taken in conjunction with the drawings, in ,which Fig. 1 represents a somewhat schematic side elevational view of a portion of the apparatus In the manufacture of sheet and strip having I frame member 32.

1938, Serial No. 226,851

embodying the present invention, certain parts being in section;

Fig. 2 shows the remainder of the apparatus, likewise in side elevation and with certain parts in section;

Fig. 3 is a sectional view along the line 3--3 of Fig. 1 illustrating one form of the mounting of the grinding wheel and the backing-up wheel;

Fig. 4 depicts the structure looking to the left of Fig. 3 along the line 4-4; and

Fig. 5 is a View similar to Fig. 3 illustrating another embodiment of the invention having a different arrangement of the grinding wheels.

Generally speaking, a strip grinder embodying my invention comprises one or more grinding wheels and one or more backing-up wheels rotating in fixed but adjustable journals, and means for feeding the strip between the said grinding wheel or wheels and backing-up wheel at a controllable speed, the novel arrangement of parts effectively overcoming the defects of prior art grinding machines and yielding a ground strip having substantially uniform gauge throughout its longitudinal and cross-sectional dimensions.

Referring more particularly to Figs. 1 and 2, it will be seen that an improved grinder embodying the present invention may comprise a coil box III, a top surface grinder I2, a bottom surface grinder l4 and a strip coiler IS. The strip l8 to be ground is placed in coiled form in the'coil box l0 and the outer end is passed through the top surface grinder l2 where the top surface is ground, then through the bottom surface grinder l4 where the bottom surface is ground, and finally to the strip coilerl6 where it is recoiled. The ground strip may thereafter be cold rolled to finished gauge as those skilled in the art will readily understand. Alternatively a single grinder l2 or it could be used and after grinding one side, the strip could be turned over and urun through a second time to grind the surface left unground inthe first pass.

' The coil box I0 is of conventional structure and is designed merely to hold the coil of strip so that it may be uncoiled smoothly, uniformly and without dimculty.

The top surface grinder 12 comprises a housing 23 having a base 22,:two'standards or housings 24 with windows 26 adapted to receive the journals for a pair of shafts 28 and. 30, and a top The pair of shafts 28 and wheel 36, respectively, in a manner hereinafter described. The journals for shaft 28 are vertically adjustableby means of the adjusting-rod 38 to regulate the distance between the grinding wheel 34 and the .backing up wheel 38 through which the strip I8 passes to be ground- Shaft 28 is power driven in the direction indicated by the arrow at/a controllable speed by a motor (not shown); In order to prevent the strip I8 from being pulled through the machine ortorn on account of the grinding action, pinch rolls 48 trollable speed by a motor (not shown).

' a separate 7 motor.

are provided in advance of the grinding wheel 34,

and these rolls 48: are power driven at a con- The motor for driving the pinch rolls 48 may be the same motor that drives the grinding'wheels or wheel rotates at a considerably higher peripheral speed than the pinch rolls and the pinch rolls 48 feed the strip I8 at the proper speed to the grinding wheels while maintaining the strip taut. The

strip I8 is absolutely under control of the operator at all times. Similar pinch rolls 42 are pro- ,vided at the exit side of thegrinding wheel 34 but they need not bepower driven. Guide rolls 44 for the strip being groundare mounted on a cross member 48 'in advanceof the pinch rolls 48. Two such guide rolls 44 are used for each strip being ground, one at either side of the strip,

and in order to accommodate strips of varying widths and numbers the-guide rolls are made a djustable laterally,for example, by providing a Mot 48. in the cross member .46 and mountin herolls 44 on stub shafts held in position by machine screws 58. j The bottom surface grinder I4 is identical with the top surface grinder I2 except that the positionsof the grinding wheel 34 and the backingup wheel'are reversed. Corresponding parts are designated by the same reference numerals.

The strip coiler may be of conventional type "comprising a framework 52 supporting a wiper 54, feed rolls 58 anda coil housing 58.

. [The shaft 28 is preferably long enough to ac commodate a plurality of grinding wheels 34, one

of which is shown in Fig. 3. The grinding wheel lars 88'. The latter are secured agains 34 is made of some suitable abrasive such as silicon carbide particles bonded together in a manner well understood by those skilled in the art; To prevent relative rotation between the shaft 28 and thegrinding wheel 34, they are keyedtogethen-as shown in Figs. 3 and 4, by

splines 68 running the full length of the shaft 28. 'Steel or other hard .metal plates 62 faced withlead or other soft metal 84 capable of grabbing orgripping into the abrasive materials of the wheel 34 are likewise keyed to the shaft 28 by thesplines 68 and held tightly against the wheel 34 by spacing collars 68 and retaini g colmovement along'the shaft 28 by set screws I8, or: the like. This novel arrangement of the grinding wheel 34 and associated parts is'of great practical importance in increasing the flexibility of the, .machine. For example,-if a 4-inch strip is.to be ground, a 4 inch grinding wheel would be put H in place on shaft 28. If a wider ornarrower strip was'to be ground thereafter, a grinding wheel of corresponding width would be substi-= tuted. Similarly, if it were desired to grind several strips simultaneously, whether they were the same width or not, the appropriate grinding wheels 84 would be placedon the shaft 28 and a the guide rolls 44 placed. in proper position to,

directthe strips to the respective grinding wheels.

The shaft 38 carrying the backing-up wheel 7 881s preferably about the same length as shaft I 28 and mounted parallel thereto. The backing- In either case the grinding up wheel may be made in semi-circular segments I2 and "held together and tightly against shaft 38 by machiiiescrews 16 set in countersunk bores in segment I2, asseen in Fig. 4. Ordinarily, one backing-up wheel is used for each grinding wheel, and the backing-up 'wheels are adapted to be mounted at any place and'in any desired num-' ber along the shaft 38 tocorrespond with the number and size of the grinding wheels being used, as described hereinabove. Preferably the backing-up wheel is slightly thinner than the grinding wheel and narrower than the strip being ground so that the edges of the strip are unsupported, as seen in Fig. 3. For example,

. in grinding'a strip of metal about 6 inches wide ,prior art grinding machines of grinding the edges thinner than the body of the strip is completely overcome. It will, ofcourse, be understood that the bottom surface grinder I4 is provided with' grinding wheels 34 and backing-up wheels 36 the same as top surface grinder I2, except that their respective positions are reversed with respect to the strip.

The improved grinder-embodying the present invention may also be used simultaneously to grind strips having different gaugesby choosing.

grinding and backing-up rollsof different diameters. The pinch rolls 48 and 42in such case, are provided with removable wheels or drums having varying outside diameters to' accommodate stripsof difierent' thicknesses. Similarly, the wheels and pinch rolls maybe shaped to accommodate various shapes such as flats, half rounds, hexagons, rounds, etc.

A modified arrangement of grinding wheelsis shown in Fig. 5 in which the backing-up wheel is replaced by a grindingwheel and two spaced '1 grinding wheels are used on theupper surface.

In this embodiment of my invention, the shafts 28 and "are both power driven and the grind- -*ing wheels on one shaft serve also as backing-up wheels for the grinding. wheels of the other shaft of the same pair. The two upper grinding wheels are spaced apart on theircommon shaft a distance practically equal to the thickness of the 'lower'grinding-wheel. As a resu'lt,-the strip-is 1 ground at the center or central regions on the lower surface and at theedges or outeriregions' on the upper'surfac'e. After passing. through the grinder once the strip may be turnedover tandem. the bottom grinder l4, being provided with three complementary grinding wheels 7 :to I grind the centerof the top'surface'and the edges of the bottom surface whereby the strip is ground and run through again in order to'grind the sur faces left unground in the first pass. Alterna- -tivelygrinders I2 and I4 may be employed on both surfaces in a single passr The embodi- 1 mentof my invention illustrated in Fig. 5fis not restricted to'the use'of'the two-.joy er one grinding wheel arrangement but may be applied with grinding wheel. combinations of threeover-two, four-over-three, etc.,. as. ,well as one-overetwo,

- two-over-three,. etc. "The. characteristic feature of the embodiment of the\inventio n illustrated 31 p mg; the grinding wheels'forgrlndlng wheels for grinding the first mentioned side of the strip. The result is that the strip is ground in narrow staggered bands running along both surfaces of the strip. This staggered arrangement of grinding wheels may be used without oppositely placed backing-up wheels in grinding strip exceeding about 0.062 inch in thickness. The width of the unsupported bands of the strip, i. e. the distance between adjacent grinding wheels may vary depending upon the thickness, composition and heat treatment of the strip being ground, and upon the distance between the grinding wheels and the pinch rolls 40 and 42, as those skilled in the art will readily understand. For example, when the distance between the points of contact of the pinch rolls 40 and the grinding rolls 34 with the strip was about 18 inches, a strip of metal about 0.125 of an inch thick and 12 inches wide was ground with grinding wheels about 4 inches thick mounted in the tWo-over-one arrangement of Fig. 5. The unsupported band at each edge of the strip was about 4 inches wide on either side of the single grinding wheel 34. The strip was turned over and passed through a second time to grind the bands left unground in the first pass. About 0.0015 of an inch of metal was ground off in each pass at a rate of about 22 feet per minute. The ground strip had satisfactory uniformity of thickness in both cross and longitudinal section and was cold rolled to finished gauge without warping ordistortion. An advantage of the staggered grinding wheel arrangementillustrated in Fig. 5 over the solid wheel arrangement of Fig. 3 is that a heavier grind on the strip may be taken without the usual buckling that would occur if it were attempted to remove the same amount of metal from a strip of the same width at the same speed with a solid wheel regardless of the type of support used to back up the strip.

Although this present invention has been described in connection with specific embodiments, modifications and variations may be resorted to, as those skilled in the ,art will understand. For example, a backing-up wheel similar'to 36 in Fig. 4 could be used in place of the lower grinding Wheel 34 of Fig. 5, and by using machines in tandem as fully described hereinabove, the strip may be ground in a single pass. Such variations and modifications are to be understood as coming within the scope of the invention as hereinabove described and set forth in the appended claims.

I claim: 1. A strip grinding apparatus comprising means for holding a coil of strip to be ground,

a top surface grinder, a bottom surface grinder, and means for 'recoiling the ground strip, said surface grinders comprising standards having vertically adjustable journals, two pairs of shafts rotatablymounted in said journals, one of the shafts of each pair having a plurality of grinding wheels mounted in spaced relation thereon and the other shaft of each pair having one less grinding wheel than the first mentioned shafts, the said grinding wheels being arranged in staggered relation on each pair of shafts-and with the shaft having the larger number of grinding" wheels arranged to grind the top of the strip on one pair of shafts and the bottom of the strip on the other pair of shafts, means including steel plates faced with lead at either side of eachgrinding wheel to position and maintain the grinding wheels in fixed but adjustable position on said grinding wheel shafts with the distance 5 from the outside faces of the outside grinding wheels on the shaft havingthe larger number of grinding wheels corresponding to the width of said strip whereby the edges of the strip are left unsupported during grinding, pinch rotatably mounted in said standards at either side of each pair of shafts, and means to drive the grinding wheel shafts and the pinch rolls at controllable speeds, and laterally adjustable guide rolls mounted in advance of the grinding 15 wheels and adapted to direct the strip to the grinding wheels. 2. A strip grinding apparatus comprising a top surface grinder and a bottom surface grinder, said surface grinders comprising standards having vertically adjustable journals, two pairs of shafts rotatably mounted in said journals, one

of said shafts ofv each pair having a plurality of grinding wheels mounted in spaced relation thereon and the other shaft of each pair having one less grinding wheel than the first mentioned shafts, the said grinding wheels being arranged in staggered relation on each pair of shafts and with the shaft having the larger number of grind- 3 ing wheels arranged to grind the top of the strip on one pair of shafts and the bottom of the strip on the other pair of shafts, means including steel plates faced with lead at either side of each grinding wheel to position and maintain the 35 grinding wheels in fixed but adjustable position on said grinding wheel shafts with the distance from the outside faces of the outside grinding wheels on the shaft having the larger number of grinding wheels corresponding to the width of said strip whereby the edges of the strip are left unsupported during grinding, pinch rolls rotatably mounted in said standards at either side of each pair of shafts, means to drive the grinding wheel shaftsand the pinch rolls at controllable speeds, and laterally adjustable guide rolls mounted in advance of the grinding wheels and adapted to direct the strip to the grinding wheels.

3. A strip grinding apparatus comprising two pairs of shafts, means for rotatably mounting said shafts, one of the shafts of each pair having a plurality' of grinding wheels mounted in spaced relation thereon and the other shaft of each pair :having one less grinding wheel than the first 4. A strip grinding apparatus comprising a pair of shafts, means rotatably mounting said shafts 65 in parallel relation, one of said shafts having a plurality of grinding wheels mounted in spaced relation thereon with the distance from the outside faces of the outside grinding wheels corresponding to the width of the strip to be ground, 0

the other of said shafts having one less grinding wheel than the first mentioned shaft, the grinding wheels on the second mentioned shaft being mounted thereon opposite the spaces between the grinding wheels on the first mentioned shaft, means to drive the grinding wheel shafts 7 rolls 10 at controllable speeds, and means for. feeding the strip to the grinding wheels at the proper speed.

5. A strip grinding apparatus adapted simul.-; taneously to grind a plurality of strips of metal comprising a pair of shafts, means rotatably mounting said shafts in parallel relation, one of I said shafts having a plurality of grinding wheels mounted thereon, the other of said shafts having a like plurality of'backing-up wheels mounted thereon, said shafts being adjusted to provide a space between each grinding wheel and associated backing-up wheel slightly less than the thickness of the strip to be ground, .a pair of guide rolls in advance of each grinding wheel adapted to direct the strips to the spaces between the grinding wheels and their associated backing-up wheels so that both edges of the strips extend laterally beyond the backing up wheels, and means for feeding the strips to the grinding wheels at the proper speed.

6. A strip grinding apparatus comprising a'firstrotatable grinding means adapted to grind spaced bands running along one surface of.a strip of metal to be ground, a second rotatable grinding means adapted to grind the other surface of said strip opposite the bands left unground by said first grinding means, means to adjust the distance between the grinding means on opposite sides of the strip, and means for producing relative motion between the strip and the grinding means longitudinally of the strip whereby the strip is progressively ground.

7. A strip grinding apparatus comprising a first grinding means adapted to grind spaced bands running along one surface of a strip of metal to be ground, a'second grinding means adapted to grind the other surface of said strip opposite the bands left unground by said first-grinding means, and means for producing relative motion between the strip and the grinding means longitudinally of the strip whereby the strip is progressively ground. 1

8. A method of grinding a metal strip comprising progressively supporting thestrip opposite the area being ground only at points inwardly from the edges whereby a band along each edge of the strip is unsupported, and progressively grinding the strip including the unsupported bands.

9. A method of grinding a metal strip comprising progressively supporting the strip opposite the area being ground only at points inwardly from'the edges whereby a band along each edge of the strip is unsupported, progressively grinding spaced bands along the strip including said unsupported bands, and subsequently grind- .ing the bands left unground in the first grinding operation.

first operation in like manner;

metal strip comprising rinding the surfaces in.

narrow staggered bands running along both sur- 4 faces of the strip by means of rotating grinding wheels which mutually support the strip for the I grinding wheels on the opposite side, and subsequently grinding the unground bands from th 11. In a method of grinding metal strip, the steps comprising progressively grinding at least 10 a portion of one surface of a' metal strip include ing bands extending inwardly from the lateral edges thereof while supporting the metal strip during the grinding operation only inwardly fromthe edges, the bands at the lateral edges of the-ll strip being without direct support, wherebyaexcessive removal of metal at the edges is prevented.

12 In the production of metal strip of prac-' tically uniform gauge in cross section for cold rolling to finished gauge without substantial warping or twisting, the grinding method'oomprising supporting the strip for the grinding operation onlywinwardly from the edges whereby a band along each edge of the strip is unsupported, and progressively grinding at least a portion of 25 the surface of the strip including said unsupported bands, whereby ground strip of substan tially uniform gauge in cross section is produced.

13. In the process of grinding metal strips by rotating grinding means to produce ground strip 30 of practically constant gauge and cross section 1 adapted for cold rolling to finished gauge without substantial warping or twisting, themethod of preventing the grinding off of an excess, of-

metal adjacent to the lateral edges of the strip into contact with the grinding means, said force being applied only inwardly -.from the lateral edges, bands adjacent tothe lateral edges of the 40 strip being given no direct support at the'time the metal is being ground therefrom, whereby ground strip ofsubstantially uniform gauge in cross section is produced. a v

14. A method of grinding both surfaces of a. metal strip comprising progressively grinding at one operation an area substantially equivalent, to the area of. one surface, said area including only one surface of bands adjacent to the lateral edges of the strip which are without direct support'during the grinding operation opposite the place being ground, and subsequently progressively grinding the area left unground in the, first 

